Eosinophil Cationic Protein (ECP)

CPT: 83520
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  • Ribonuclease 3

Expected Turnaround Time

4 - 7 days

Related Information

Related Documents

Specimen Requirements




0.5 mL

Minimum Volume

0.3 mL (Note: This volume does not allow for repeat testing.)


NMR lipoprofile serum-separator tube (No. 60360). Other tubes should not be used as they may produce erroneous results.


Allow the sample to stand for 60 to 120 minutes to release the ECP in the cells prior to centrifugation. Separate the serum after 60 to 120 minutes and transfer to a plastic transport tube.

Storage Instructions


Stability Requirements



Room temperature

5 days


14 days


14 days

Freeze/thaw cycles

Stable x3

Causes for Rejection

Nonserum sample received; non-Greiner tube collected; grossly hemolyzed or lipemic samples

Test Details


Measurement of the level of Eosinophil Cationic Protein (ECP) in serum


This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

BD plastic serum-separator tubes should not be used as they will produce erroneous results.

ECP has limited utility as a diagnostic marker of asthma because changes in serum ECP level have been registered in other atopic diseases like allergic rhinitis, but also in conditions not related to the eosinophil inflammation, such as bacterial sinusitis.1 Also, ECP application is limited only to the allergic type of asthma.



Reference Interval

4−54 μg/L

Additional Information

Eosinophils are effector cells that play a role in allergic and nonallergic inflammation and mediate host immune response to parasites, bacteria and viruses.1-3 The most prominent feature of these cells is large cytoplasmic granules, each containing four basic proteins, the most plentiful of which is eosinophil cationic protein (ECP).4 ECP is a protein with ribonuclease activity that is released during eosinophil activation. While the full physiologic role of ECP has not been completely defined, this protein has been attributed with cytotoxic, neurotoxic, fibrosis-promoting and immune-regulatory functions.2,4,5 Studies suggest that ECP may play a role in regulating mucosal and immune cells and may directly fight parasitic, bacterial and viral infections.4

ECP is often elevated in diseases in which an eosinophil-mediated tissue inflammation plays a role.2,4-8 Levels can be increased in patients with eosinophilic esophagitis.9-13 Measuring ECP levels has been used to evaluate eosinophil-mediated allergic inflammation, asthma and rhinitis.2 Levels can be increased during both seasonal and perennial rhinitis and may reflect current allergen exposure.2,14 In atopic dermatitis, ECP has been shown to correlate with the symptoms and total clinical score.15

Eosinophilic inflammation is a relatively common feature of asthma.14,16-19 Although not diagnostic for asthma, elevated ECP levels are thought to reflect the degree of asthma-related bronchial eosinophilic inflammation.14,20 Increased ECP levels correspond to symptom onset and can precede bronchial hyper-reactivity.2,16 ECP has been used to assess asthma severity and support the management of anti-inflammatory therapy.5,20 It should be noted, however, that ECP is better correlated to symptom score than to lung function parameters, especially in children with mild and moderate asthma.14

ECP levels can be increased in a number of gastrointestinal disorders, including eosinophil intestinal diseases (esophagitis, gastroenteritis and colitis), gastrointestinal food allergy and intestinal parasitic infections.2 ECP levels can also be increased in non−IgE-mediated conditions, including nonallergic asthma with aspirin intolerance, respiratory infections, sinonasal polyposis and idiopathic hypereosinophilia (HES) syndrome.2,4 ECP has also been used as a disease activity marker in Churg-Strauss syndrome (CSS), a condition that is also known as allergic granulomatosis or allergic angiitis.21 CSS is a disorder marked by blood vessel inflammation that can restrict blood flow to vital organs and tissues, sometimes permanently damaging them.2


1. Topic RZ, Dodig S. Eosinophil cationic protein--current concepts and controversies. Biochem Med (Zagreb). 2011;21(2):111-121.22135850
2. Moneret-Vautrin DA. Is the seric eosinophil cationic protein level a valuable tool of diagnosis in clinical practice? Rev Med Interne. 2006 Sep;27(9):679-683.16647168
3. Venge P, Byström J, Carlson M, et al. Eosinophil cationic protein (ECP): Molecular and biological properties and the use of ECP as a marker of eosinophil activation in disease. Clic Exp Allergy. 1999 Sep; 29(9):1172-1186.10469025
4. Bystrom J, Amin K, Bishop-Bailey D. Analysing the eosinophil cationic protein—A clue to the function of the eosinophil granulocyte. Respir Res. 2011 Jan 14;12:10.21235798
5. Venge P. Monitoring the allergic inflammation. Allergy. 2004 Jan;59(1):26-32.14674929
6. Tiotiu A. Biomarkers in asthma: state of the art. Asthma Res Pract. 2018 Dec 21;4:10.30598830
7. Hyvärinen MK, Kotaniemi-Syrjänen A, Reijonen TM, Piippo-Savolainen E, Korppi M. Eosinophil activity in infants hospitalized for wheezing and risk of persistent childhood asthma. Pediatr Allergy Immunol. 2010 Feb;21(1 Pt 1):96-103.19793065
8. Nielsen LP, Peterson CG, Dahl R. Serum eosinophil granule proteins predict asthma risk in allergic rhinitis. Allergy. 2009 May;64(5):733-737.19133919
9. Doménech Witek J, Jover Cerdà V, Gil Guillén V, Clar JBD, Pacheco RR. Assessing eosinophilic cationic protein as a biomarker for monitoring patients with eosinophilic esophagitis treated with specific exclusion diets. World Allergy Organ J. 2017 Mar 23;10(1):12.28360963
10. Hines BT, Rank MA, Wright BL, et al. Minimally invasive biomarker studies in eosinophilic esophagitis: A systematic review. Ann Allergy Asthma Immunol. 2018 Aug;121(2):218-228.29753832
11. Schlag C, Miehlke S, Heiseke A, et al. Peripheral blood eosinophils and other non-invasive biomarkers can monitor treatment response in eosinophilic oesophagitis. Aliment Pharmacol Ther. 2015 Nov;42(9):1122-1130.26314389
12. Schlag C, Pfefferkorn S, Brockow K, et al. Serum eosinophil cationic protein is superior to mast cell tryptase as marker for response to topical corticosteroid therapy in eosinophilic esophagitis. J Clin Gastroenterol. 2014 Aug;48(7):600-606.24177377
13. Min SB, Nylund CM, Baker TP, et al. Longitudinal Evaluation of Noninvasive Biomarkers for Eosinophilic Esophagitis. J Clin Gastroenterol. 2017 Feb;51(2):127-135.27479142
14. Prehn A, Seger RA, Faber J, et al. The relationship of serum-eosinophil cationic protein and eosinophil count to disease activity in children with bronchial asthma. Pediatr Allergy Immunol. 1998 Nov;9(4):197-203.9920218
15. Czech W, Krutmann J, Schöpf E, Kapp A. Serum eosinophil cationic protein (ECP) Is a sensitive measure for disease activity in atopic dermatitis. Br J Dermatol. 1992 Apr;126(4):351-355.1571256
16. Tomassini M, Magrini L, De Petrillo G, et al. Serum levels of eosinophil cationic protein in allergic diseases and natural allergen exposure. J Allergy Clin Immunol. 1996 Jun;97(6):1350-1355.8648032
17. Sorkness C, McGill K, Busse WW. Evaluation of serum eosinophil cationic protein as a predictive marker for asthma exacerbation in patients with persistent disease. Clin Exp Allergy. 2002 Sep;32(9):1355-1359.12220475
18. Peona V, De Amici M, Quaglini S, et al. Serum eosinophilic cationic protein: Is there a role in respiratory disorders. J Asthma. 2010 Mar;47(2):131-134.20170318
19. Niimi A, Amitani R, Suzuki K, Tanaka E, Murayama T, Kuze F. Serum eosinophil cationic protein as a marker of eosinophilic inflammation in asthma. Clin Exp Allergy. 1998 Feb;28(2):233-240.9515598
20. Koh GC, Shek LP, Goh DY, Van Bever H, Koh DS. Eosinophil cationic protein: Is it useful in asthma? A systematic review. Respir Med. 2007 Apr;101(4):696-705.17034998
21. Guilpain P, Auclair JF, Tamby MC, et al. Serum eosinophil cationic protein: A marker of disease activity in Churg-Strauss syndrome. Ann N Y Acad Sci. 2007 Jun;1107:392-399.17804567


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
004180 ECP 25638-8 004181 ECP ug/L 25638-8

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